Crosville busses around here were driver only and parcels could be placed on at stops. The driver would usually guess the weight and charge accordingly.
That reminds me, I once was waiting for a bus to put a parcel on. I was there in plenty of time and this bus arrived, driven by a bloke who is now a friend of mine. I got on the bus (I was a spotty teenager in those days!!) and said, "Can you take this parcel to Bangor" driver said No! "Why not?" I asked indignantly "Because I'm only going to RAF Valley". I had got there soon enough and, unbeknown to me, there was a bus about two minutes before the Bangor one which did the round trip to RAF Valley. I didn't think to check the sign on the front of the bus! I bet the passengers enjoyed that one!!